/*
 * (C) 2011-2012 by Holger Hans Peter Freyther <zecke@selfish.org>
 * (C) 2011-2012 by On-Waves
 * All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <openbsc/mgcp.h>
#include <openbsc/mgcp_internal.h>

#include <osmocom/core/application.h>
#include <osmocom/core/talloc.h>
#include <string.h>
#include <limits.h>

#define AUEP1	"AUEP 158663169 ds/e1-1/2@172.16.6.66 MGCP 1.0\r\n"
#define AUEP1_RET "200 158663169 OK\r\n"
#define AUEP2	"AUEP 18983213 ds/e1-2/1@172.16.6.66 MGCP 1.0\r\n"
#define AUEP2_RET "500 18983213 FAIL\r\n"
#define EMPTY	"\r\n"
#define EMPTY_RET NULL
#define SHORT	"CRCX \r\n"
#define SHORT_RET "510 000000 FAIL\r\n"

#define MDCX_WRONG_EP "MDCX 18983213 ds/e1-3/1@172.16.6.66 MGCP 1.0\r\n"
#define MDCX_ERR_RET "510 18983213 FAIL\r\n"
#define MDCX_UNALLOCATED "MDCX 18983214 ds/e1-1/2@172.16.6.66 MGCP 1.0\r\n"
#define MDCX_RET "400 18983214 FAIL\r\n"
#define MDCX3 "MDCX 18983215 1@mgw MGCP 1.0\r\n"
#define MDCX3_RET "200 18983215 OK\r\n"		\
		 "I: 1\n"			\
		 "\n"				\
		 "v=0\r\n"			\
		 "o=- 1 23 IN IP4 0.0.0.0\r\n"	\
		 "c=IN IP4 0.0.0.0\r\n"		\
		 "t=0 0\r\n"			\
		 "m=audio 0 RTP/AVP 126\r\n"	\
		 "a=rtpmap:126 AMR/8000\r\n"

#define SHORT2	"CRCX 1"
#define SHORT2_RET "510 000000 FAIL\r\n"
#define SHORT3	"CRCX 1 1@mgw"
#define SHORT4	"CRCX 1 1@mgw MGCP"
#define SHORT5	"CRCX 1 1@mgw MGCP 1.0"

#define CRCX	 "CRCX 2 1@mgw MGCP 1.0\r\n"	\
		 "M: sendrecv\r\n"		\
		 "C: 2\r\n"			\
		 "\r\n"				\
		 "v=0\r\n"			\
		 "c=IN IP4 123.12.12.123\r\n"	\
		 "m=audio 5904 RTP/AVP 97\r\n"	\
		 "a=rtpmap:97 GSM-EFR/8000\r\n"

#define CRCX_RET "200 2 OK\r\n"			\
		 "I: 1\n"			\
		 "\n"				\
		 "v=0\r\n"			\
		 "o=- 1 23 IN IP4 0.0.0.0\r\n"	\
		 "c=IN IP4 0.0.0.0\r\n"		\
		 "t=0 0\r\n"			\
		 "m=audio 0 RTP/AVP 126\r\n"	\
		 "a=rtpmap:126 AMR/8000\r\n"


#define CRCX_ZYN "CRCX 2 1@mgw MGCP 1.0\r"	\
		 "M: sendrecv\r"		\
		 "C: 2\r\r"			\
		 "v=0\r"			\
		 "c=IN IP4 123.12.12.123\r"	\
		 "m=audio 5904 RTP/AVP 97\r"	\
		 "a=rtpmap:97 GSM-EFR/8000\r"

#define CRCX_ZYN_RET "200 2 OK\r\n"		\
		 "I: 2\n"			\
		 "\n"				\
		 "v=0\r\n"			\
		 "o=- 2 23 IN IP4 0.0.0.0\r\n"	\
		 "c=IN IP4 0.0.0.0\r\n"		\
		 "t=0 0\r\n"			\
		 "m=audio 0 RTP/AVP 126\r\n"	\
		 "a=rtpmap:126 AMR/8000\r\n"

#define DLCX	 "DLCX 7 1@mgw MGCP 1.0\r\n"	\
		 "C: 2\r\n"

#define DLCX_RET "250 7 OK\r\n"			\
		 "P: PS=0, OS=0, PR=0, OR=0, PL=0, JI=0\r\n" \
		 "X-Osmo-CP: EC TIS=0, TOS=0, TIR=0, TOR=0\r\n"

#define RQNT	 "RQNT 186908780 1@mgw MGCP 1.0\r\n"	\
		 "X: B244F267488\r\n"			\
		 "S: D/9\r\n"

#define RQNT2	 "RQNT 186908781 1@mgw MGCP 1.0\r\n"	\
		 "X: ADD4F26746F\r\n"			\
		 "R: D/[0-9#*](N), G/ft, fxr/t38\r\n"

#define RQNT1_RET "200 186908780 OK\r\n"
#define RQNT2_RET "200 186908781 OK\r\n"

struct mgcp_test {
	const char *name;
	const char *req;
	const char *exp_resp;
};

static const struct mgcp_test tests[] = {
	{ "AUEP1", AUEP1, AUEP1_RET },
	{ "AUEP2", AUEP2, AUEP2_RET },
	{ "MDCX1", MDCX_WRONG_EP, MDCX_ERR_RET },
	{ "MDCX2", MDCX_UNALLOCATED, MDCX_RET },
	{ "CRCX", CRCX, CRCX_RET },
	{ "MDCX3", MDCX3, MDCX3_RET },
	{ "DLCX", DLCX, DLCX_RET },
	{ "CRCX_ZYN", CRCX_ZYN, CRCX_ZYN_RET },
	{ "EMPTY", EMPTY, EMPTY_RET },
	{ "SHORT1", SHORT, SHORT_RET },
	{ "SHORT2", SHORT2, SHORT2_RET },
	{ "SHORT3", SHORT3, SHORT2_RET },
	{ "SHORT4", SHORT4, SHORT2_RET },
	{ "RQNT1", RQNT, RQNT1_RET },
	{ "RQNT2", RQNT2, RQNT2_RET },
	{ "DLCX", DLCX, DLCX_RET },
};

static const struct mgcp_test retransmit[] = {
	{ "CRCX", CRCX, CRCX_RET },
	{ "RQNT1", RQNT, RQNT1_RET },
	{ "RQNT2", RQNT2, RQNT2_RET },
	{ "MDCX3", MDCX3, MDCX3_RET },
	{ "DLCX", DLCX, DLCX_RET },
};

static struct msgb *create_msg(const char *str)
{
	struct msgb *msg;

	msg = msgb_alloc_headroom(4096, 128, "MGCP msg");
	int len = sprintf((char *)msg->data, str);
	msg->l2h = msgb_put(msg, len);
	return msg;
}

static void test_messages(void)
{
	struct mgcp_config *cfg;
	int i;

	cfg = mgcp_config_alloc();

	cfg->trunk.number_endpoints = 64;
	mgcp_endpoints_allocate(&cfg->trunk);

	mgcp_endpoints_allocate(mgcp_trunk_alloc(cfg, 1));

	for (i = 0; i < ARRAY_SIZE(tests); i++) {
		const struct mgcp_test *t = &tests[i];
		struct msgb *inp;
		struct msgb *msg;

		printf("Testing %s\n", t->name);

		inp = create_msg(t->req);
		msg = mgcp_handle_message(cfg, inp);
		msgb_free(inp);
		if (!t->exp_resp) {
			if (msg)
				printf("%s failed '%s'\n", t->name, (char *) msg->data);
		} else if (strcmp((char *) msg->data, t->exp_resp) != 0)
			printf("%s failed '%s'\n", t->name, (char *) msg->data);
		msgb_free(msg);
	}

	talloc_free(cfg);
}

static void test_retransmission(void)
{
	struct mgcp_config *cfg;
	int i;

	cfg = mgcp_config_alloc();

	cfg->trunk.number_endpoints = 64;
	mgcp_endpoints_allocate(&cfg->trunk);

	mgcp_endpoints_allocate(mgcp_trunk_alloc(cfg, 1));

	for (i = 0; i < ARRAY_SIZE(retransmit); i++) {
		const struct mgcp_test *t = &retransmit[i];
		struct msgb *inp;
		struct msgb *msg;

		printf("Testing %s\n", t->name);

		inp = create_msg(t->req);
		msg = mgcp_handle_message(cfg, inp);
		msgb_free(inp);
		if (strcmp((char *) msg->data, t->exp_resp) != 0)
			printf("%s failed '%s'\n", t->name, (char *) msg->data);
		msgb_free(msg);

		/* Retransmit... */
		printf("Re-transmitting %s\n", t->name);
		inp = create_msg(t->req);
		msg = mgcp_handle_message(cfg, inp);
		msgb_free(inp);
		if (strcmp((char *) msg->data, t->exp_resp) != 0)
			printf("%s failed '%s'\n", t->name, (char *) msg->data);
		msgb_free(msg);
	}

	talloc_free(cfg);
}

static int rqnt_cb(struct mgcp_endpoint *endp, char _tone)
{
	ptrdiff_t tone = _tone;
	endp->cfg->data = (void *) tone;
	return 0;
}

static void test_rqnt_cb(void)
{
	struct mgcp_config *cfg;
	struct msgb *inp, *msg;

	cfg = mgcp_config_alloc();
	cfg->rqnt_cb = rqnt_cb;

	cfg->trunk.number_endpoints = 64;
	mgcp_endpoints_allocate(&cfg->trunk);

	mgcp_endpoints_allocate(mgcp_trunk_alloc(cfg, 1));

	inp = create_msg(CRCX);
	msgb_free(mgcp_handle_message(cfg, inp));
	msgb_free(inp);

	/* send the RQNT and check for the CB */
	inp = create_msg(RQNT);
	msg = mgcp_handle_message(cfg, inp);
	if (strncmp((const char *) msg->l2h, "200", 3) != 0) {
		printf("FAILED: message is not 200. '%s'\n", msg->l2h);
		abort();
	}

	if (cfg->data != (void *) '9') {
		printf("FAILED: callback not called: %p\n", cfg->data);
		abort();
	}

	msgb_free(msg);
	msgb_free(inp);

	inp = create_msg(DLCX);
	msgb_free(mgcp_handle_message(cfg, inp));
	msgb_free(inp);
	talloc_free(cfg);
}

struct pl_test {
	int		cycles;
	uint16_t	base_seq;
	uint16_t	max_seq;
	uint32_t	packets;

	uint32_t	expected;
	int		loss;
};

static const struct pl_test pl_test_dat[] = {
	/* basic.. just one package */
	{ .cycles = 0, .base_seq = 0, .max_seq = 0, .packets = 1, .expected = 1, .loss = 0},
	/* some packages and a bit of loss */
	{ .cycles = 0, .base_seq = 0, .max_seq = 100, .packets = 100, .expected = 101, .loss = 1},
	/* wrap around */
	{ .cycles = 1<<16, .base_seq = 0xffff, .max_seq = 2, .packets = 4, .expected = 4, .loss = 0},
	/* min loss */
	{ .cycles = 0, .base_seq = 0, .max_seq = 0, .packets = UINT_MAX, .expected = 1, .loss = INT_MIN },
	/* max loss, with wrap around on expected max */
	{ .cycles = INT_MAX, .base_seq = 0, .max_seq = UINT16_MAX, .packets = 0, .expected = ((uint32_t)(INT_MAX) + UINT16_MAX + 1), .loss = INT_MAX }, 
};

static void test_packet_loss_calc(void)
{
	int i;
	printf("Testing packet loss calculation.\n");

	for (i = 0; i < ARRAY_SIZE(pl_test_dat); ++i) {
		uint32_t expected;
		int loss;
		struct mgcp_rtp_state state;
		struct mgcp_rtp_end rtp;
		memset(&state, 0, sizeof(state));
		memset(&rtp, 0, sizeof(rtp));

		state.initialized = 1;
		state.base_seq = pl_test_dat[i].base_seq;
		state.out_stream.last_seq = pl_test_dat[i].max_seq;
		state.cycles = pl_test_dat[i].cycles;

		rtp.packets = pl_test_dat[i].packets;
		mgcp_state_calc_loss(&state, &rtp, &expected, &loss);

		if (loss != pl_test_dat[i].loss || expected != pl_test_dat[i].expected) {
			printf("FAIL: Wrong exp/loss at idx(%d) Loss(%d vs. %d) Exp(%u vs. %u)\n",
				i, loss, pl_test_dat[i].loss,
				expected, pl_test_dat[i].expected);
		}
	}
}

static void test_mgcp_stats(void)
{
	printf("Testing stat parsing\n");

	uint32_t bps, bos, pr, _or, jitter;
	struct msgb *msg;
	int loss;
	int rc;

	msg = create_msg(DLCX_RET);
	rc = mgcp_parse_stats(msg, &bps, &bos, &pr, &_or, &loss, &jitter);
	printf("Parsing result: %d\n", rc);
	if (bps != 0 || bos != 0 || pr != 0 ||  _or != 0 || loss != 0 || jitter != 0)
		printf("FAIL: Parsing failed1.\n");
	msgb_free(msg);

	msg = create_msg("250 7 OK\r\nP: PS=10, OS=20, PR=30, OR=40, PL=-3, JI=40\r\n");
	rc = mgcp_parse_stats(msg, &bps, &bos, &pr, &_or, &loss, &jitter);
	printf("Parsing result: %d\n", rc);
	if (bps != 10 || bos != 20 || pr != 30 || _or != 40 || loss != -3 || jitter != 40)
		printf("FAIL: Parsing failed2.\n");
	msgb_free(msg);
}

struct rtp_packet_info {
	float txtime;
	int len;
	char *data;
};

struct rtp_packet_info test_rtp_packets1[] = {
	/* RTP: SeqNo=0, TS=0 */
	{0.000000, 20, "\x80\x62\x00\x00\x00\x00\x00\x00\x11\x22\x33\x44"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* RTP: SeqNo=1, TS=160 */
	{0.020000, 20, "\x80\x62\x00\x01\x00\x00\x00\xA0\x11\x22\x33\x44"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* RTP: SeqNo=2, TS=320 */
	{0.040000, 20, "\x80\x62\x00\x02\x00\x00\x01\x40\x11\x22\x33\x44"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* Repeat RTP timestamp: */
	/* RTP: SeqNo=3, TS=320 */
	{0.060000, 20, "\x80\x62\x00\x03\x00\x00\x01\x40\x11\x22\x33\x44"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* RTP: SeqNo=4, TS=480 */
	{0.080000, 20, "\x80\x62\x00\x04\x00\x00\x01\xE0\x11\x22\x33\x44"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* RTP: SeqNo=5, TS=640 */
	{0.100000, 20, "\x80\x62\x00\x05\x00\x00\x02\x80\x11\x22\x33\x44"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* Double skip RTP timestamp (delta = 2*160): */
	/* RTP: SeqNo=6, TS=960 */
	{0.120000, 20, "\x80\x62\x00\x06\x00\x00\x03\xC0\x11\x22\x33\x44"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* RTP: SeqNo=7, TS=1120 */
	{0.140000, 20, "\x80\x62\x00\x07\x00\x00\x04\x60\x11\x22\x33\x44"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* RTP: SeqNo=8, TS=1280 */
	{0.160000, 20, "\x80\x62\x00\x08\x00\x00\x05\x00\x11\x22\x33\x44"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* Non 20ms RTP timestamp (delta = 120): */
	/* RTP: SeqNo=9, TS=1400 */
	{0.180000, 20, "\x80\x62\x00\x09\x00\x00\x05\x78\x11\x22\x33\x44"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* RTP: SeqNo=10, TS=1560 */
	{0.200000, 20, "\x80\x62\x00\x0A\x00\x00\x06\x18\x11\x22\x33\x44"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* RTP: SeqNo=11, TS=1720 */
	{0.220000, 20, "\x80\x62\x00\x0B\x00\x00\x06\xB8\x11\x22\x33\x44"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* SSRC changed to 0x10203040, RTP timestamp jump */
	/* RTP: SeqNo=12, TS=34688 */
	{0.240000, 20, "\x80\x62\x00\x0C\x00\x00\x87\x80\x10\x20\x30\x40"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* RTP: SeqNo=13, TS=34848 */
	{0.260000, 20, "\x80\x62\x00\x0D\x00\x00\x88\x20\x10\x20\x30\x40"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
	/* RTP: SeqNo=14, TS=35008 */
	{0.280000, 20, "\x80\x62\x00\x0E\x00\x00\x88\xC0\x10\x20\x30\x40"
		       "\x01\x23\x45\x67\x89\xAB\xCD\xEF"},
};

void mgcp_patch_and_count(struct mgcp_endpoint *endp, struct mgcp_rtp_state *state,
			  struct mgcp_rtp_end *rtp_end, struct sockaddr_in *addr,
			  char *data, int len);

static void test_packet_error_detection(void)
{
	int i;

	struct mgcp_trunk_config trunk;
	struct mgcp_endpoint endp;
	struct mgcp_rtp_state state;
	struct mgcp_rtp_end *rtp = &endp.net_end;
	struct sockaddr_in addr = {0};
	char buffer[4096];

	printf("Testing packet error detection.\n");

	memset(&trunk, 0, sizeof(trunk));
	memset(&endp, 0, sizeof(endp));
	memset(&state, 0, sizeof(state));

	trunk.number_endpoints = 1;
	trunk.endpoints = &endp;
	endp.tcfg = &trunk;

	/* This doesn't free endp but resets/frees all fields of the structure
	 * and invokes mgcp_rtp_end_reset() for each mgcp_rtp_end. OTOH, it
	 * expects valid pointer fields (either NULL or talloc'ed), so the
	 * memset is still needed. It also requires that endp.tcfg and
	 * trunk.endpoints are set up properly. */
	mgcp_free_endp(&endp);

	rtp->payload_type = 98;
	endp.allow_patch = 1;

	for (i = 0; i < ARRAY_SIZE(test_rtp_packets1); ++i) {
		struct rtp_packet_info *info = test_rtp_packets1 + i;

		OSMO_ASSERT(info->len <= sizeof(buffer));
		OSMO_ASSERT(info->len >= 0);
		memmove(buffer, info->data, info->len);

		mgcp_patch_and_count(&endp, &state, rtp, &addr,
				     buffer, info->len);

		printf("TS: %d, dTS: %d, TS Errs: in %d, out %d\n",
		       state.out_stream.last_timestamp,
		       state.out_stream.last_tsdelta,
		       state.in_stream.err_ts_counter,
		       state.out_stream.err_ts_counter);
	}
}

int main(int argc, char **argv)
{
	osmo_init_logging(&log_info);

	test_messages();
	test_retransmission();
	test_packet_loss_calc();
	test_rqnt_cb();
	test_mgcp_stats();
	test_packet_error_detection();

	printf("Done\n");
	return EXIT_SUCCESS;
}